Question

34 multiple choice 1 point
during a uv-visible spectroscopy experiment, a student notes 2 wavelength peak measurements at 580nm and 680nm. what region of the electromagnetic spectrum were these peaks observed?
ultra-violet region
visible region
both ultra-violet and visible region

35 multiple choice 1 point
which of the following diatomic molecules is joined by a double covalent bond?
\\(n_2\\)
\\(o_2\\)
\\(cl_2\\)

36 multiple choice 1 point
a molecule that has a single covalent bond is ______.
\\(co_2\\)
\\(cl_2\\)
\\(co\\)

37 multiple choice 1 point
construct the molecule \\(h_2o\\). what are the bond angles in the structure?
\\(109.5^\circ\\)
\\(107^\circ\\)
\\(104.5^\circ\\)

38 multiple choice 1 point
how many electrons are shared in a single covalent bond?
1
2
3

Explanation:

Identify electromagnetic regions for given wavelengths

Using the Electromagnetic Spectrum Wavelengths knowledge point, we analyze the wavelengths \(580\text{ nm}\) and \(685\text{ nm}\). The visible light spectrum ranges from approximately \(400\text{ nm}\) to \(700\text{ nm}\). Since both \(580\text{ nm}\) (yellowish-orange) and \(685\text{ nm}\) (red) fall within this range, these peaks are in the visible region.

Determine diatomic molecule with a double covalent bond

Using the Lewis Structures knowledge point, we draw the structures for the options:

• \(\text{N}_2\) has a triple bond (\(\text{N}\equiv\text{N}\)).
• \(\text{O}_2\) has a double bond (\(\text{O}=\text{O}\)).
• \(\text{Cl}_2\) has a single bond (\(\text{Cl}-\text{Cl}\)).

Thus, \(\text{O}_2\) is joined by a double covalent bond.

Identify the molecule with a single covalent bond

Using the Lewis Structures knowledge point, we evaluate the bonding in each molecule:

• \(\text{CO}_2\) contains two double bonds (\(\text{O}=\text{C}=\text{O}\)).
• \(\text{Cl}_2\) contains a single covalent bond (\(\text{Cl}-\text{Cl}\)).
• \(\text{CO}\) contains a triple bond (\(\text{C}\equiv\text{O}\)).

Thus, \(\text{Cl}_2\) is the molecule with a single covalent bond.

Determine the bond angle of water

Using the VSEPR Theory knowledge point, \(\text{H}_2\text{O}\) has a central oxygen atom with two bonding pairs and two lone pairs, giving it a bent molecular geometry. The strong repulsion from the two lone pairs compresses the tetrahedral angle from \(109.5^\circ\) down to approximately \(104.5^\circ\).

Determine electrons shared in a single covalent bond

A single covalent bond consists of one shared pair of electrons. Therefore, there are \(2\) electrons shared in a single covalent bond.

Identify the formula for rubidium disulfide

Rubidium is an alkali metal forming a \(\text{Rb}^+\) cation. Disulfide is a diatomic anion \(\text{S}_2^{2-}\). Combining these to form a neutral ionic compound yields \(\text{Rb}_2\text{S}_2\).

Answer:

Question 34

• ultra-violet region
• visible region (Correct answer)
• both ultra-violet and visible region

Question 35

• \(\text{N}_2\)
• \(\text{O}_2\) (Correct answer)
• \(\text{Cl}_2\)

Question 36

• \(\text{CO}_2\)
• \(\text{Cl}_2\) (Correct answer)
• \(\text{CO}\)

Question 37

• \(109.5^\circ\)
• \(107^\circ\)
• \(104.5^\circ\) (Correct answer)

Question 38

• 1
• 2 (Correct answer)
• 3

Question 39

• \(\text{Rb}_2\text{S}_2\) (Correct answer)